Warren Gatland says the decision to drop Peter O’Mahony from his match-day 23 for Saturday’s second Test as a “tough” call and said the Munster flanker was unlucky to miss out.

The Corkman captained the team against New Zealand in the 30-15 defeat at Eden Park last weekend but is not involved at all for the return fixture as the coach recalls Sam Warburton to his starting team with CJ Stander taking a place on the bench.

Gatland has also included England second-row Maro Itoje at the expense of George Kruis, while Johnny Sexton has come in for Ben Te’o with Owen Farrell moving to the centre.

The coach delivered the news to O’Mahony privately before informing the squd overnight and said he wanted his side to have more impact at ruck time, the area where Warburton is strongest.

Warren Gatland the head coach of the Lions looks on prior to kickoff during the 2017 British & Irish Lions tour match between the Hurricanes and the British & Irish Lions at the Westpac Stadium (Photo by David Rogers/Getty Images)

“It was a tough call,” Gatland said of his decision to axe O’Mahony.

“We looked at that and felt it was an opportunity to bring in Sam and Maro who both made an impact off the bench last week.

“We need to get some pressure on the ball and that’s something Sam is excellent at doing and he has got some rugby under his belt now.

“We could have put Peter on the bench and we had a long discussion about that, but CJ Stander has had an outstanding Six Nations and was good the other night with his carries and his physicality, so the impact he is able to bring off the bench could be significant.

“Look, Peter has been very unlucky. He has done a great job for us in terms of the games he has been involved in and the captaincy.

“He’s unlucky enough that we can have got choices and can make changes and use different combinations.”

Gatland is hoping that Warburton and Sean O’Brien can combine well along with Taulupe Faletau in the Lions’ back-row.

“Sam has been brilliant,” he said.

“He knows he was a little bit short of game time. We need to be more effective at the breakdown and competing more.

“The All Blacks got some go-forward and some quick quality ball last week so we need to be more effective.

“His role is to get in there. Even though he is playing six, he is as good as any player in world rugby in terms of being able to get on the ball and either create turnovers, win penalties or slow the ball down.

“He’s well aware of his role and making sure defensively he gets pretty hard off the line and wins those defensive collisions. We saw that when he came on, the impact that he had. Hopefully that combination with Sean O’Brien works effectively.

“Sean has had an outstanding tour to date and I think the balance of those two will be pretty good.”

Although Te’o did well in the first Test, particularly when combatting Sonny Bill Williams’ physicality Gatland has no reservations about pitting Farrell and Sexton together from the start for the first time.

“They haven’t started together but they have had quite a bit of time together,” he said.

“The combination against the Crusaders was good and they had a bit of time last week. It gives us two ball-players, two kicking options on the right foot at first and second receiver, with the left foot options with Jonathan Davies and Elliot Daly as well.

“We are happy with the mix.

“One concern we have got is looking at the long-range weather forecast it doesn’t look good for Saturday night, so may have to change tactically the way we are going to play.

“We need to do a job defensively on Sonny Bill Williams too. He was pretty direct against us and got a couple of offloads away. It’s important we try and shut him down.”

Gatland wants to see an improved effort from his side in a number of areas.

“All we can ask from the players is to try and have an attitude,” he said.

“In fairness to the All Blacks they played exceptionally well. They were very direct in the way they played. They played a bit of 'Warrenball' didn’t they, whatever that is.

“We are aware of how physical they were, so we have got to match that physicality on Saturday night.

“They were excellent and deserved their win. We played some good rugby and when we could keep the ball we did stress them and put them under pressure. We have just got to make sure we keep the ball for longer periods.

“We have got to stop their momentum off nine. But they may come with a different plan. They may look to throw the ball around, they may plan to kick the ball a bit more and we have got to be ready for that.

“Discipline is a key for us, making sure we don’t give away soft unnecessary penalties. There were two or three last week which changed the momentum of the game. We saw that against the Hurricanes again on Tuesday night.

“There were a couple of soft penalties which were pretty costly for us in the second half.

“We have obviously got to be more physical up front and the players are aware of that and we have spoken about that as a group.”